Any luck printing with the Visual Extra Fine (0.06mm) profile with PVA supports?

[jasonrohrer 8]

I have a brand new UM S3, and I'm printing PLA with PVA supports

 

I've had quite a bit of luck printing with the Normal and Fine profile with PVA supports, but it hasn't been reliable with the Visual Extra Fine profile.  The project file is attached.

 

One time, the bottom layer of the triangles didn't print correctly... one or two of the "bars" of the triangle just weren't there.

 

Another time, the bottom worked, but later on, an upper layer got gummed up, and the support stopped printing correctly.

 

This is relatively new PVA filament that has been stored consistently in PrintDry vacuum-sealed boxes (that my local UltiMaker dealer sent me home with when I bought the S3):

 

https://www.printdry.com/product/vacuum-sealed-filament-container/

 

I also leave the silica gel pack that came with the filament in the vacuum box.  And I seal/pump and vacuum the box when it's empty, to keep the gel from absorbing from the room while the filament is being used.

 

It's also winter here, and quite dry in the house.  Below 25% humidity.  But I haven't been leaving the PVA out between prints.  Still, it has been on the spool holder *during* prints.

 

So, last night, I put it in a Sovol 3D drying box, which heats to 50c and has a little fan.  I left it in there for more than 12 hours.  And now I'm trying the print again, leaving the PVA in the drying box, and holding it at 50c during the print.  There's a little hole in the lid of the drying box for the filament to pass through.  That leaves only 1 foot of filament exposed to the air, between the drying box and the bottom of the filament feeder on the printer.

 

 

And it's still not working great.  Bottom layer missed a few struts, but I just let it go to see what would happen.  It seems to have recovered somewhat, but now some of the upper layers are missing support areas too.  The model itself seems to be sufficiently supported so far, even with the incomplete supports.  But it's definitely not what I want to see.  I don't like the feeling of "taking my chances" with derelict supports.

 

It's now 2 hours through a 4-hour print.... we'll see what happens.

 

 

I've had much more reliable results using the AquaSys 120 dissolvable filament.  However, Cura doesn't have finer profiles by default for that filament.  Not sure of the reason for that, but I can't even get down to 0.1mm (0.15mm is the finest it will go in Cura).

UMS3_supportTest_v4_PVA_ExtraFine.3mf

[jasonrohrer 8]

3 hours into the 4 hour print, it looks like this.

 

It's getting messed up enough there near the top that I doubt it will properly support the next layer of PLA when needed.

Edited January 5, 2023 by jasonrohrer

[jasonrohrer 8]

52 minutes left, and it looks like this now:

 

[Gero 54]

The problem here is that with such a thin layer height and such a small object, very little material is conveyed. PVA is a material that does not like very slow extrusion rates. Therefore, with small objects at this layer height, problems will arise very quickly. Here it can help to set the horizontal expansion much higher, simply to keep the nozzle busy for longer.

 

We have four Ultimaker printers running and print mostly with PVA support. 
I can only strongly recommend replacing the Ultimaker PVA. 
Of the many alternatives on the market, Ultimaker PVA is the clear winner in terms of clean dissolving. By this I mean that the water does not become cloudy when dissolving. This makes it easy to see how far the supports have dissolved. 

 

In all other categories, the Ultimaker PVA scores rather mediocre to partly poor. 
By far the best PVA to print is BASF's BVOH. There are virtually no extrusion problems here, so that it is also possible to print with the fine profile. 

[jasonrohrer 8]

Yes, I've been investigating BASF BVOH.

 

Is there a particular material profile that you like to use for it?

 

I see that it's not present in the UltiMaker Marketplace.

[jasonrohrer 8]

Also, have you ever compared AquaSys 120 to BVOH?

 

I'm having quite a bit of solid reliability and good luck with AquaSys 120 so far.  I just kicked off a 17-hour print, which I'd never trust to PVA, and 2-hours in, it's humming along perfectly.

 

I just ordered the BASF BVOH, though.

 

I was sold on the (very expensive) S3 with the idea that PVA-support printing "just works," as long as you keep the PVA dry.  That hasn't been the case for me.

 

The fact that the printer SHIPS with a spool of PVA...

 

I even had the salesman demo a PVA-support print for me before I purchased the machine.  It's noteworthy, in retrospect, that he printed an upside-down mushroom that needed *very little* PVA support.  He had the classic "nested gyro spinner" on hand, which they printed in the store at some point in the past... but it might be one of those "roboticists treasure their videos" kinda things---here's an amazing 30-hour print from the one day that PVA supports actually worked for us.

 

If AquaSys or BVOH is a more reliable option, I think UltiMaker should move toward recommending those, and probably just discontinue UltiMaker PVA.